Spanner beam hanger assembly

ABSTRACT

A hanger for supporting a spanner beam used in the construction of bridge decks and the like. A bracket includes a flat tongue which rests on a girder and opposed side plates which receive one end of the spanner beam therebetween. A camming pin is inserted through opposed openings in the side plates and rotated to become tightly lodged in a supportive position beneath the spanner beam. A Z-shaped accessory plate may be used to support the bracket in an alternative position a short distance below the top of the girder. A leveling mechanism which rests on top of the girder receives the bracket tongue and is adjustable in order to vary the elevation of the spanner beam.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a reusable hanger assembly for temporarilysupporting a spanner beam during the construction of bridge decks andother elevated concrete slabs.

The forms normally used in construction projects to support the concretewhile it hardens include wooden spanner beams and plywood panels. Thespanner beams are suspended on hangers between the main structuralgirders and the plywood panels are installed on top of the spanner beamsto provide a flat surface for receiving the concrete. After the concretehas hardened sufficiently to become self-supporting, the forms aredisassembled and removed for further use.

The types of hangers currently used to support the spanner beams sufferfrom various disadvantages, such as structural weakness, high cost, andassembly difficulties. Also, since most existing hangers receive thespanner beam relatively loosely, the assembled forms lack rigidity andare able to shift in position or even collapse when the concrete ispoured. Known hangers are further unsatisfactory in that the disassemblyand removal of the forms requires considerable time and effort and oftenresults in damage to the forms. More importantly, the disassembly or"wrecking" of the forms involves danger to the workmen because thespanner beams and plywood panels are released together and the entirebulk of the forms must therefore be handled simultaneously.

In one type of prior art hanger, the spanner beam is received in abracket and supported on a tapered wedge member which is insertedbeneath the spanner beam by wedging action. The main disadvantage ofthis type of hanger is its lack of stability, since the weight of theconcrete exerts a force which tends to work the wedge member out of thebracket. As a result, the forms are likely to collapse unless the wedgemember is driven in so tightly that its removal is difficult, in whichcase the time, trouble and danger involved in disassembling the forms isincreased substantially.

A further deficiency in the prior art is the lack of a practical maansfor varying the haunch of the concrete slab, or its elevation relativeto the main structural beams or girders. Existing hanger assembliestypically support the spanner beam at a constant elevation with respectto the girders so that the haunch also remains constant, even though thevertical deflection of the girders varies along their lengths. Theconcrete slab is therefore not level throughout its length, a resultthat is particularly undesirable in bridges having a lengthy spanbecause of the large girder deflection near the center of the bridge.Even those hangers that permit haunch variation support the spanner beamonly at discrete or stepped levels so that vertical adjustmentthroughout a continuous range is not achieved.

In view of the foregoing drawbacks associated with existing spanner beamhangers, it is the primary goal of the present invention to provide animproved hanger assembly for supporting the forms used in theconstruction of elevated concrete slabs such as bridge decks and thelike.

More specifically, it is an object of the invention to provide a hangerassembly which supports a spanner beam in a rigid position between apair of spaced girders. It is an important feature of the invention thateach end of the spanner beam is tightly retained in the hanger assemblysuch that the hangers, spanner beams, and girders form a rigid structurein the assembled condition.

In conjunction with the preceding object, it is a further object of theinvention to provide a hanger assembly of the character described thatsupports the spanner beam with increased stability and resists anytendency of the spanner beam to release when the concrete is poured.

Another object of the invention is to provide a hanger assembly of thecharacter described which permits the assembly and disassembly of theforms to be carried out quickly, easily and safely.

Yet another object of the invention is to provide a hanger assembly ofthe character described that includes adjustable means for varying thehaunch of the concrete slab throughout a continuous range.

A further object of the invention is to provide a hanger assembly of thecharacter described that is economically manufactured and yetconstructed ruggedly for repeated use.

DETAILED DESCRIPTION OF THE INVENTION

In the accompany drawings which form a part of the specification and areto be read in conjunction therewith, and in which like referencenumerals are employed to represent like parts in the various views:

FIG. 1 is a perspective view of a spanner beam supported between spacedI-beam girders by a pair of hanger assemblies constructed in accordancewith a preferred embodiment of the invention;

FIG. 2 is a fragmentary, elevational view taken in cross section throughan I-beam and showing a hanger assembly positioned on the W-beam tosupport one end of the spanner beam, with a plywood panel installed ontop of the spanner beam and a bridge deck formed on a plywood panel;

FIG. 3 is a fragmentary, elevational view similar to FIG. 2, but showingthe components of the hanger assembly arranged in an alternativeposition to support the spanner beam below the top of the I-beam;

FIG. 4 is an enlarged, exploded perspective view of the components ofthe hanger assembly, including an adjustable leveling mechanism;

FIG. 5 is a fragmentary, perspective view of a hanger assemblypositioned on an I-beam and showing the camming bar inserted beneath thespanner beam with its slot facing upwardly, the spanner beam being shownin broken lines and a tool that is useful for rotating the camming barbeing illustrated;

FIG. 6 is an enlarged, fragmentary perspective view showing a hangerassembly and leveling mechanism in position to support one end of thespanner beam from an I-beam; and

FIG. 7 is an elevational view taken in cross section through spacedI-beams and showing a pair of hanger assemblies and leveling mechanismsin position to support the spanner beam between the I-beams, with aplywood panel installed on top of the spanner beam and a bridge deckformed on the plywood panel.Referring now to the drawings in detail andinitially to FIG. 1, a pair of identical hanger assemblies constructedin accordance with the invention are each generally designated byreference numeral 10. Hanger assemblies 10 are used to support theopposite ends of a wooden spanner beam 11 such that the spanner beamextends perpendicularly between a pair of parallel I-beams 12. EachI-beam 12 includes a horizontal upper flange 13, a horizontal lowerflange 14, and a vertical web 15 that interconnects flanges 13 and 14 attheir centers. Spanner beam 11 is rectangular in cross section and isincluded in the forms that are commonly used in the construction ofbridge decks and other elevated concrete slabs. The length of spannerbeam 11 is such that it extends between the edges of the I-beam flangesto span the distance between the two I-beams 12.

Each hanger assembly 10 includes a bracket 16 which is best illustratedin its structural details in FIG. 4. A pair of parallel side plates 17and 18 form the opposite sides of bracket 16. Plates 17 and 18 areoriented vertically and are spaced from one another a distance slightlygreater than the thickness of spanner beam 11 so that the spanner beammay be received therebetween. Plates 17 and 18 gradually taper from topto bottom and are rounded at their bottom ends. A flat, horizontal toppanel 19 of rectangular shape is integral with side plates 17 and 18 andinterconnects the side plates at their upper edges to form the top ofbracket 16. A flat, rectangular tongue 20 is formed as a continuousextension of top panel 19 and projects horizontally a considerabledistance beyond side plates 17 and 18. Respective circular openings 21and 22 are formed in alignment with one another through the lowerportions of side plates 17 and 18. The upper edge of each opening 21 and22 is located below top panel 19 a distance slightly greater than thevertical dimension of a spanner beam inserted between the side plates 17and 18. A small aperture 23 of a size to receive a nail is formedthrough each side plate 17 and 18 somewhat below the top of the plateand near one lateral edge thereof.

A beam support means comprising a rolled pin 24 is included in eachhanger assembly to support spanner beam 11. The length of pin 24 isgreater than the distance between side plates 17 and 18, while the sizeof the pin is somewhat smaller than the diameter of openings 21 and 22.The pin is generally C-shaped in section with a cylindrical exteriorsurface. The longitudinal edges of the pin do not meet, therebyproviding a slot 25 extending throughout the length of the pin. Slot 25provides eccentricity to the exterior surface of the pin so as to securethe spanner beam 11 with a camming action against the upper plate 19 aswill be more fully explained hereinafter.

FIG. 5 illustrates a wrench tool 30 useful to rotate the eccentric pin24. Tool 30 includes an elongate handle 31 which terminates in anenlarged head 32. Mounted on the head 32 is a cylindrical socket 33which is sized to fit closely around pin 24. An internal lug 34 projectsinwardly from the wall of socket 33 and is sized to fit into slot 25 ofpin 24.

Again with reference to FIG. 4, each hanger assembly may further includea generally Z-shaped accessory member 26. Member 26 includes a flat base27 having a rectangular configuration and a length slightly greater thanthe combined length of top panel 19 and tongue 20 of bracket 16. Anintermediate web 28 is connected at one edge to the end of base 27 andextends perpendicularly therefrom. The opposite edge of web 28 connectsto a flat flange 29 which extends outwardly from the web at a rightangle. Flange 29 is of substantially the same size and shape as thebracket tongue 20.

In use as shown in FIG. 1, one of the hanger assemblies 10 is suspendedfrom each of the I-beams 12 to support spanner beam 11 between theI-beams with tongue 20 bearing on top of the upper I-beam flange 13 withthe edges of side plates 17 and 18 contacting the edge of the flange 13.When installing a hanger assembly 10, one end of spanner beam 11 isinserted between side plates 17 and 18. Base 27 is held flatly againstthe bottom of spanner beam 11, and pin 24 is inserted through the plateopenings 21 and 22 and beneath the spanner beam and accessory member 26.With particular reference to FIG. 5, slot 25 is oriented upwardly as pin24 is inserted beneath the spanner beam so that sufficient clearance ispresented between the flat underside of base 27 and the bottom edges ofopenings 21 and 22 to permit the pin 24 to easily fit through openings21 and 22.

Pin 24 is thereafter rotated from the FIG. 5 position to a position suchas shown in FIG. 2. A tool 30 of the nature previously described may beemployed to facilitate rotation of the pin 24. With socket element 33inserted over the end of pin 24 and lug 34 projecting into slot 25, thetool handle 31 is turned to rotate pin 24 from the FIG. 5 position,whereupon the cylindrical pin surface comes into engagement with theunderside of the accessory member base 27. The resulting camming actionpresses spanner beam 11 upwardly against top panel 19 and tightly lodgespin 24 in a supportive position beneath the spanner beam and base 27.Spanner beam 11 is thereby rigidly retained within bracket 16 with atight wedging fit.

It should be noted that in the application of the hanger assembly asshown in FIG. 2, member 26 is only an accessory piece and may beomitted. In such instance, the pin 24 would cam against the lowersurface of the beam 11 instead of the plate 27. Although accessorymember 26 is included in the foregoing description, it is primarily in astored position in FIG. 2 and plays a more significant structural rolein subsequent applications of the hanger assembly as will becomeapparent.

After a plurality of spanner beams have been positioned between I-beams12, a rectangular plywood panel 35 is installed on top of the spannerbeams and hanger assemblies, as shown in FIG. 2. Concrete is then pouredonto panel 35 and cured to form the bridge deck 36. In the preferredembodiment, tongue 20 is 1/4 inch thick and panel 35 is 3/4 inch thickso that a haunch of approximately 1 inch will be formed between the topof I-beam 12 and the bottom of bridge deck 36 when the hanger assemblyis employed as in FIG. 2.

Once the concrete has hardened sufficiently to become self-supporting,the hanger assemblies 10, spanner beams 11 and panel 35 are removed forfurther use. To disassemble the forms, pin 24 is rotated until slot 25mates with the plate 27 or the beam 11. Pin 24 is thereby loosenedsomewhat and may be withdrawn from openings 21 and 22 to release spannerbeam 11. For safety purposes and to temporarily support spanner beam 11as pin 24 is withdrawn, a nail 37 may be driven into the spanner beamthrough aperture 23 and thereafter removed when it is desired to releasethe spanner beam. With the beam 11 removed, bracket 16 is then pulledaway from I-beam 12 to withdraw tongue 20 from the top of flange 13 andpermit removal of the bracket and the plywood panel 35. If anyresistance in removing the bracket is encountered as may be caused byconcrete adhering to tongue 20, this may easily be overcome by a slightwedging of the bracket to dislodge the tongue 20.

If the bottom of bridge deck 36 is to be at the same elevation as thetop of I-beams 12, accessory member 26 may be used to suspend bracket 16from the I-beam in the alternative position shown in FIG. 3. The flatflange 29 of member 26 is placed on top of I-beam 12 with base 27inserted between side plates 17 and 18 such that top panel 19 restsflatly on top of the base plate 27. Spanner beam 11 is inserted betweenside plates 17 and 18 and held against base 27 as pin 24 is inserted inopenings 21 and 22 with slot 25 facing upwardly. Subsequent rotation ofpin 24 results in camming action which presses spanner beam 11 upwardlyagainst base 27 and tightly lodges pipe 24 beneath the spanner beam.Panel 35 is then installed and bridge deck 36 is formed in the mannerpreviously related. The height of the web 28 is such that plywood panel35 will rest on top of bracket 16 with the top surface of the plywoodpanel at the same elevation as the top surface of the upper I-beamflange 13.

In the FIG. 3 application of the hanger device, plate 29 serves the samefunction as tongue 20 to bear on the girder 12. The bracket 16 may bereversed (but not necessarily) so that the rear edge of plate 19 engagesthe web. 28 of the extension accessory 26 in FIG. 3.

To strip the forms and hanger assemblies once the concrete is set, pin24 is rotated to orient slot 25 upwardly I-beam and permit the pin to bewithdrawn from openings 21 and 22. After the spanner beam has beenremoved from bracket 16, the bracket is slid away from the I- beam untilits top panel 19 clears the end of base 27 to separate the bracket fromaccessory member 26. Member 26 is then pulled or pried to withdraw itsflange 29 from the concrete and permit the accessory member and panel 35to be removed.

It is frequently desirable to vary the haunch of bridge deck 36 atcertain areas, such as when the vertical deflection of I-beams 12 isconsiderable at their central portions. An adjustable leveling mechanism40 is therefore included for use with hanger assemblies 10 to permitvariation in the haunch of the bridge deck. Referring particularly toFIG. 4, leveling mechanism 40 includes a small rectangular plate 41.Internally threaded openings are formed through plate 41 near itsopposite ends to receive screws 42 and 43. Each screw 42 and 43 has abottom end, a threaded shank, and an enlarged hexagonal head. A metalstrip 44 projects upwardly from the top surface of plate 41 at a centralportion thereof and is spaced a slight distance above plate 41. Strip 44and plate 41 thereby cooperate to present a narrow slot 45 of a size toclosely but removably receive tongue 20 or flange 29.

Leveling mechanism 40 is applied on top of I-beam 12 by placing the flatbottom ends of screws 42 and 43 thereon, as shown in FIGS. 6 and 7.Plate 41 is spaced above the top of the I-beam in a horizontalorientation and may be vertically adjusted by turning screws 42 and 43appropriately. Tongue 20 of the hanger installed on a beam as shown inFIG. 2 or extension flange 29 of the hanger installed on a beam as shownin FIG. 3 is inserted in slot 45 to support the bracket 16 and spannerbeam 11. Plywood panel 35 may be placed over a plurality of assembledspanner beams to receive the concrete which forms bridge deck 36. Theadjustment means provided by screws 42 and 43 permits the haunch ofbridge deck 36 to be varied throughout a continuous range to compensatefor increasing deflection of the girders 12 toward the centers thereof.

The removal of the forms after bridge deck 36 has hardened is carriedout substantially as previously described. Pin 24 is rotated to permitwithdrawal of the pin and the release of spanner beam 11. Bracket 16 isthen pulled away from leveling mechanism 40 to withdraw tongue 20 (orflange 29) from slot 45. Bracket 16 and plywood panel 35 are removed forfurther use, although leveling mechanism 40 remains embedded in theconcrete.

For illustrative purposes, the use of hanger assemblies 10 has beendescribed in connection with the construction of a bridge deck. However,it is to be understood that the hanger assemblies are equally useful inthe construction of any type of elevated concrete slab which employsspanner beams to support temporary forms.

From the foregoing it will be seen that this invention is one welladapted to attain all the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

Since many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:
 1. A hanger assembly forsupporting a beam member from a support surface, said assemblycomprising:a bracket having a pair of parallel side plates spaced apartsufficiently to receive therebetween the beam member at the end thereofand a top web member interconnecting said side plates to overlie thebeam member received between said side plates, said bracket furtherincluding openings formed through said side plates in alignment with oneanother, said openings substantially positioned beneath the beam memberwhen said member is received between said side plates and is engagedwith said top web; an extension member comprising a base platepositionable to underlie said top web and adapted to be disposed betweensaid top web and said beam member when said bracket is installedthereon, an intermediate web integrally joined to one end of said baseplate and extending perpendicularly upwardly therefrom, and a tongueplate integrally joined to the top of said web and extendingperpendicularly laterally therefrom to overlie said support surface; aneccentric beam support member having a length greater than the distancebetween said side plates and sized to be received through said openingsin said side plates, and beam support member having a camming surfaceand being rotatable within said openings whereby when said beam memberis received between said side plates said beam support member may berotated to tightly and grippingly lock said beam member between said topweb and the camming surface of said support member.
 2. A hanger assemblyfor supporting a beam member from a support surface, said assemblycomprising:a bracket having a pair of parallel side plates spaced apartsufficiently to receive therebetween the beam member at the end thereofand a top web member interconnecting said side plates to overlie thebeam member received between said side plates, said bracket furtherincluding openings formed through said side plates in alignment with oneanother, said openings substantially positioned beneath the beam memberwhen said member is received between said side plates and is engagedwith said top web; an extension member associated with said top web andprojecting outwardly from said side plates to overlie said supportsurface; an eccentric beam support member having a length greater thanthe distance between said side plates and sized to be received throughsaid openings in said side plates, said beam support member having acamming surface and being rotatable within said openings whereby whensaid beam member is received between said side plates said beam supportmember may be rotated to tightly and grippingly lock said beam memberbetween said top web and the camming surface of said support member; anda leveling appliance to overlyingly bear on said support surface, saidappliance including a tongue receiving member removably but supportinglyconnected to said extension member, and adjustment means for selectivelyvarying the elevation of said tongue receiving member above said supportsurface.
 3. The hanger assembly as in claim 2, said tongue receivingmember having an internally threaded bore and said adjustment meansincluding a threaded shank disposed within said threaded bore with thelower end of said shank engaging said support surface whereby rotationof said shank imparts vertical displacement to said tongue receivingmember.